4-(meth)acrylamidomethyl)-pyrazoles and -isoxazoles, their preparation and their use

Abstract

Novel 4-[(meth)acrylamidomethyl]-pyrazoles and -isoxazoles of the general formula <IMAGE> (I) where R is hydrogen or methyl, R1 is hydrogen, methyl or ethyl, R2 and R3 may be identical or different and are each alkyl of 1 to 6 carbon atoms or unsubstituted or substituted aryl of 6 to 20 carbon atoms, and X is oxygen or an NR4 group where R4 is hydrogen or a radical having the meanings of R2 or R3, a process for their preparation, and the use of these compounds in particular for polymerization and the preparation of homopolymers and copolymers, are described.

We claim: 
     
       1. A 4-[(meth)acrylamidomethyl]-pyrazole or -isoxazole of the formula (I) ##STR8## where R, R 1 , R 2 , R 3  and X independently of one another have the following meanings: R is hydrogen or methyl, R 1  is hydrogen, methyl or ethyl, R 2  and R 3  may be identical or different and are each alkyl of 1 to 6 carbon atoms or unsubstituted or substituted aryl of 6 to 20 carbon atoms and X is oxygen or an NR 4  group, where R 4  is hydrogen or a radical having the meanings of R 2  or R 3 . 
     
     
       2. A 4-[(meth)acrylamidomethyl]-pyrazole as claimed in claim 1, wherein, in the formula (I), R and R 1  are each hydrogen, R 2  and R 3  are each methyl or phenyl and X is NR 4  where R 4  is hydrogen or phenyl. 
     
     
       3. A 4-[(meth)acrylamidomethyl]-isoxazole as claimed in claim 1, wherein, in the formula (I), R and R 1  are each hydrogen, R 2  and R 3  are each methyl or phenyl and X is oxygen. 
     
     
       4. A process for the preparation of a 4-[(meth)acrylamidomethyl]-pyrazole or -isoxazole, comprising the following steps: (1) condensing a 1,3-diketone of the formula (II) ##STR9##  where R 2  and R 3  may be identical or different and independently of one another are each alkyl of 1 to 6 carbon atoms or unsubstituted methyl, t-butyl or phenyl substituted aryl of 6 to 20 carbon atoms, with an N-methylol(meth)acrylamide of the formula (III) ##STR10##  where R is hydrogen or methyl and R 1  is hydrogen, methyl or ethyl, in a strong acid as a reaction medium, thereby obtaining a 2-[(meth)acrylamidomethyl]-1,3-diketone of the formula (IV) ##STR11##  where R, R 1 , R 2  and R 3  have the meanings stated above for the formulae (II) and (III), and (2) condensing the said 2-[(meth)acrylamidomethyl]-1,3-diketone of the formula IV with a hydrazine or hydroxylamine, thereby obtaining a 4-[(meth)acrylamidomethyl]-pyrazole or -isoxazole of the formula (I) ##STR12##  where R, R 1 , R 2 , R 3  and X independently of one another have the following meanings: R is hydrogen or methyl, R 1  is hydrogen, methyl or ethyl, R 2  and R 3  may be identical or different and are each alkyl of 1 to 6 carbon atoms or unsubstituted or methyl, t-butyl or phenyl substituted aryl of 6 to 20 carbon atoms and X is oxygen or an NR 4  group, where R 4  is hydrogen or a radical having the meanings of R 2  or R 3 .   
     
     
       5. A process as claimed in claim 4, wherein, in the formulae (I), (II), (III) and (IV), R and R 1  are each hydrogen and R 2  and R 3  are each methyl or phenyl. 
     
     
       6. A process as claimed in claim 4, wherein in the second step, a 2-[(meth)acrylamidomethyl]-1,3-diketone of the formula (IV) is condensed with a hydrazinium salt or a hydrazine of the formula (V)   NH.sub.2 --NH--R.sup.4                                     (V)     where R 4  is hydrogen or a radical having the meanings of R 2  or R 3 .   
     
     
       7. A process as claimed in claim 4, wherein, in the second step, a 2-[(meth)acrylamidomethyl]-1,3-diketone of the formula (IV) is condensed with hydroxylamine or a hydroxylammonium salt. 
     
     
       8. A process for the preparation of a 4-[(meth)-acrylamidomethyl]-pyrazole or -isoxazole, comprising the following steps: (1) condensing a 1,3-diketone of the formula (II) ##STR13##  where R 2  and R 3  may be identical or different and independently of one another are each alkyl of 1 to 6 carbon atoms or unsubstituted or methyl, t-butyl or phenyl substituted aryl of 6 to 20 carbon atoms, with an equimolar amount of an N-methylol(meth)acrylamide of the formula III ##STR14##  where R is hydrogen or methyl and R 1  is hydrogen, methyl or ethyl, in 2 to 20 times the weight of the 1,3-diketone of the general formula (II) of a strong acid as a reaction medium at from 15° to 40° C. for a time period of from 1 to 48 hours, thereby obtaining a 2-[(meth)acrylamidomethyl]-1,3-diketone of the formula (IV) ##STR15##  where R, R 1 , R 2  and R 3  have the meanings stated above for the formulae (II) and (III),   (2) isolating the said 2-[(meth)acrylamidomethyl]-1,3-diketone of the formula IV by pouring the reaction mixture obtained from process step 1 on a large excess of ice, thus precipitating the said 2-[(meth)acrylamidomethyl]-1,3-diketone, and   (3) condensing the said 2-[(meth)acrylamidomethyl]-1,3-diketone of the formula IV with an equimolar amount of a hydrazine or hydroxylamine in an aqueous reaction medium at the boiling point of said medium, thereby obtaining a 4-[(meth)acrylamidomethyl]-pyrazole or -isoxazole of the formula (I) ##STR16##  where R, R 1 , R 2 , R 3  and X independently of one another have the following meanings: R is hydrogen or methyl, R 1  is hydrogen, methyl or ethyl, R 2  and R 3  may be identical or different and are each alkyl of 1 to 6 carbon atoms or unsubstituted or substituted aryl of 6 to 20 carbon atoms and X is oxygen or an NR 4  group, R 4  is hydrogen or a radical having the meanings of R 2  or R 3 .